Novel SMIF lead screw transmission system and method, storage medium and electronic equipment

Abstract

The invention discloses a novel SMIF lead screw transmission system which comprises a shell of a groove structure. The movement part comprises a first movement assembly and a second movement assembly, the first movement assembly is arranged on the upper portion of the shell and fixed to a bottom plate of the shell, and the second movement assembly is arranged on the lower portion of the first movement assembly and fixed to a bottom plate of the shell; the second movement assembly is driven by the first movement assembly to do up-down linear movement along the inner wall of the shell, and the first movement assembly is driven by a servo motor; and the SMIF lead screw adopts a ball screw and is arranged between the first movement assembly and the second movement assembly, and the first movement assembly drives the second movement assembly to convey wafers through the ball screw. The high-precision ball screw is adopted to replace a traditional penetrating screw, the ball screw is in rolling friction through line contact, higher bearing capacity and impact resistance are achieved, and load stress is effectively dispersed.

Description

Technical Field

[0001] This invention relates to the field of semiconductor transport technology, particularly to the field of SMIF wafer transport technology, and specifically to a novel SMIF screw drive system, method, storage medium, and electronic device. Background Technology

[0002] In existing SMIF wafer transfer structures, SMIF often uses a traditional through-screw drive system to achieve linear motion. However, in high-precision wafer transfer, the traditional screw system is susceptible to factors such as vibration, insufficient preload, and load changes, which can cause jitter during operation, affecting transfer and positioning accuracy, and even causing wafer surface damage or equipment wear.

[0003] Existing technologies have attempted to improve this situation by adjusting the lubrication and the lead screw fixing base. 1. By identifying abnormal SMIF operation and regularly lubricating the lead screw components with grease to reduce frictional resistance and ensure smooth and stable movement, this solution is very labor-intensive to implement on a large scale of SMIFs, affecting normal production operations. 2. Changing the lead screw fixing base from PVC to aluminum alloy reduces wear caused by material factors, thus reducing the inevitable vibration caused by long-term lead screw movement. However, since the root cause is the overall influence of the lead screw and motor, this solution cannot completely solve the problem. Therefore, an optimization design method is proposed to optimize the lead screw transmission system.

[0004] This invention aims to solve the jitter problem of the lead screw system in the existing SMIF transfer structure. It proposes a new design method to achieve high stability and low jitter in the wafer transfer process by improving the lead screw structure, preload control, vibration suppression and other technologies. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a new SMIF lead screw drive system, method, storage medium, and electronic device. This invention is applicable to solving the problem of lead screw system jitter in existing SMIF transmission structures.

[0006] To achieve the above objectives, the first technical solution adopted by the present invention is: a novel SMIF lead screw drive system, characterized in that it comprises: The housing has a groove structure; The motion section includes a first motion component and a second motion component. The first motion component is disposed on the upper part of the housing and fixed to the bottom plate of the housing. The second motion component is disposed on the lower part of the first motion component. The second motion component moves vertically up and down along the inner wall of the housing under the drive of the first motion component. The first motion component is driven by a servo motor. The SMIF lead screw is a ball screw and is disposed between the first motion component and the second motion component. The first motion component drives the second motion component to transport the wafer through the ball screw.

[0007] Optionally, the first motion component adopts an integrated design that combines a reducer, motor, and driver into one unit.

[0008] Optionally, the first motion component further includes a coupling, one end of which is connected to the servo motor and the other end of which is connected to the ball screw.

[0009] Optionally, the lower end of the coupling is further provided with a bearing fixing seat, and the distance between the bearing fixing seat and the coupling is not greater than a first predetermined distance.

[0010] Optionally, a ball screw nut is provided below the bearing mounting base.

[0011] Optionally, the first motion component further includes a heat sink, which is disposed on the outside of the coupling and connected at one end to a servo motor mounting base and at the other end to a bearing mounting base.

[0012] Optionally, the heat sink is attached to the bottom plate of the housing.

[0013] The second technical solution adopted in this invention is: a new SMIF ball screw drive method, applied to any of the new SMIF ball screw drive systems described in the invention, the method comprising: driving a ball screw by the servo motor to transport the wafer along the SMIF ball screw to achieve high-precision linear motion.

[0014] The third technical solution adopted in this invention is: a computer-readable storage medium storing computer instructions, which, when executed, cause the computer to execute the new SMIF lead screw drive method.

[0015] The fourth technical solution adopted in this invention is: the application provides a computer device, which includes a processor and a memory, the memory storing computer instructions, the computer instructions being operated by the processor to execute a new SMIF ball screw drive method.

[0016] The beneficial effects of this invention are: This invention replaces the traditional through-type lead screw with a high-precision ball screw. The ball screw, through its line contact rolling friction design, has higher load-bearing capacity, rigidity, and impact resistance, effectively dispersing load stress and reducing deformation and vibration caused by load changes. A servo motor replaces the stepper through-type motor, which occupies less space. The design integrates the reducer, motor, and driver into one unit, with optimized reducer and electromagnetic design and a self-developed heat dissipation system to improve heat dissipation speed. The assembly process is simple, and the coupling allows for a good fit with the lead screw. Attached Figure Description

[0017] Figure 1 This is a first schematic diagram of the structure of the new SMIF screw drive system of the present invention; Figure 2 This is a second schematic diagram of the structure of the new SMIF screw drive system of the present invention; Figure 3 This is the third schematic diagram of the structure of the new SMIF lead screw drive system of the present invention; Figure 4 This is a schematic diagram of the operation interface of the new SMIF lead screw drive system of the present invention.

[0018] Reference numerals: 1. Housing; 2. Moving part; 21. First moving component; 22. Servo motor; 3. Second moving component; 4. Coupling; 5. Bearing mounting seat; 6. Ball screw nut; 7. SMIF screw; 8. Heat sink. Detailed Implementation

[0019] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0020] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0021] In existing SMIF wafer transfer structures, SMIF often uses a traditional through-screw drive system to achieve linear motion. However, in high-precision wafer transfer, the traditional screw system is susceptible to factors such as vibration, insufficient preload, and load changes, which can cause jitter during operation, affecting transfer and positioning accuracy, and even causing wafer surface damage or equipment wear.

[0022] This invention aims to solve the jitter problem of the lead screw system in the existing SMIF transfer structure. It proposes a new design method to achieve high stability and low jitter in the wafer transfer process by improving the lead screw structure, preload control, vibration suppression and other technologies.

[0023] This invention provides a novel SMIF (Standard Mechanical Interface) screw drive system. SMIF is a key system in semiconductor equipment used for wafer transport and storage in the semiconductor manufacturing field. Its core function is to achieve efficient and safe transport of wafers between different process equipment, such as lithography machines, etching machines, and cleaning machines, through a standardized mechanical interface, while reducing the time wafers are exposed to the external environment, thereby reducing the risk of contamination and improving production yield. The SMIF system consists of three parts: a wafer cassette, a transport interface, and an automated transport system. The wafer cassette adopts a sealed design, with its interior filled with nitrogen to maintain a clean environment. Its front-opening structure allows for precise docking with the equipment interface, avoiding manual contact. The transport interface is usually integrated into the front-end module of the semiconductor equipment, and the wafer cassette is automatically loaded and unloaded through a robotic arm or track system. The automated transport system is responsible for moving the wafer cassette between equipment, and common forms include AGVs (Automated Guided Vehicles) and overhead conveyor chains. Its technological advantages lie in: standardized interfaces: conforming to international standards such as SEMI E47 and E63, ensuring compatibility between equipment from different manufacturers; cleanliness control: through a sealed structure and airflow circulation system, the time the wafer is exposed to a non-clean environment is controlled within seconds; efficiency improvement: the single transmission time can be shortened to less than 10 seconds, which is 3-5 times more efficient than traditional manual operation. The current SMIF equipment market exhibits two major trends: integration: combining with AI scheduling systems to optimize transmission paths through real-time data analysis and reduce equipment idle time; customization: developing special wafer cassettes that are high-temperature resistant and corrosion-resistant, specifically tailored to the characteristics of third-generation semiconductor materials.

[0024] Current methods, such as manually lubricating the screw periodically and altering the screw mounting base, cannot completely eliminate the screw vibration problem and are extremely labor-intensive for large-scale SMIF systems, impacting the normal operation of the main equipment. Changing the screw mounting base has also confirmed that this is only a temporary measure and cannot completely solve the vibration problem. Therefore, a new design method is proposed to improve the current situation regarding the screw system vibration problem in existing SMIF transmission structures.

[0025] In one specific embodiment of this application, the system includes: a housing 1, which has a groove structure; a motion unit 2, which includes a first motion component 21 and a second motion component 3. The motion unit 2 is used for wafer transport. The first motion component 21 is disposed on the upper part of the housing 1 and fixed to the bottom plate of the housing 1. The second motion component 3 is disposed on the lower part of the first motion component 21. The second motion component 3 moves vertically up and down along the inner wall of the housing 1 under the drive of the first motion component 21. The first motion component is driven by a servo motor 22. An SMIF screw 7, which is a ball screw, is disposed between the first motion component 21 and the second motion component 3. The first motion component 21 drives the second motion component 3 to transport the wafer through the ball screw. In the semiconductor manufacturing process, wafer transport is crucial for IC manufacturing. To ensure the quality of wafers when they flow between different processes and to avoid wafers being contaminated by dust particles or other pollutants, Standard Mechanical Interface (SMIF) technology is used. Using SMIF technology can greatly improve production efficiency. SMIF technology centers on the concept of "isolation technology," aiming to prevent product contamination by enclosing the wafer in an ultra-clean environment while relaxing the cleanliness requirements outside this enclosed environment. This significantly reduces FAB operating costs while ensuring yield.

[0026] In this embodiment, the ball screw is an ideal product for converting rotary motion into linear motion, or vice versa. Ball screws are the most commonly used transmission components in machine tools and precision machinery. Their main function is to convert rotary motion into linear motion, or torque into axial reciprocating force, while also possessing high precision, reversibility, and high efficiency. Due to their very low frictional resistance, ball screws are widely used in various industrial equipment and precision instruments. A ball screw consists of a screw, nut, steel balls, preload plates, a reversing device, and a dust collector. Its function is to convert rotary motion into linear motion, which is a further extension and development of the Eckham screw. The significant meaning of this development is that it transforms the bearing's action from sliding to rolling.

[0027] In one specific embodiment of this application, the first motion component 21 adopts an integrated design of reducer, motor, and driver. The motor, reducer, driver, and encoder constitute the basic skeleton of the robot's actuator. Together, they support the robot's efficient, precise, and reliable motion. A servo motor is used instead of a stepper motor. The new servo motor has a low space occupation, and the integrated design of reducer, motor, and driver greatly reduces the space required.

[0028] In this embodiment, the driver acts as the "brain," receiving instructions (such as position, speed, and torque) from the upper-level controller (PLC, motion control card, etc.) and executing complex current vector control algorithms. The motor acts as the "heart," typically a high-performance permanent magnet synchronous servo motor, converting electrical energy into precise rotary motion. The reducer acts as the "muscle," typically a high-precision, low-backlash planetary reducer or harmonic reducer, converting the motor's high-speed, low-torque output into low-speed, high-torque output, and improving the system's rigidity and load capacity. The integrated design encapsulates these three components within a compact housing, directly connecting them via internal buses (such as the encoder feedback line and power line between the driver and motor), eliminating the need for complex external wiring.

[0029] Specifically, the main advantages of adopting an integrated reducer, motor, and driver design are: High integration and space saving: The size and weight are significantly smaller than separate solutions, making it ideal for space-constrained automation equipment, such as robot joints and dense assembly lines. Simplified installation and wiring: Only power and communication cables need to be connected, such as EtherCAT, CANopen, and Profinet, greatly simplifying mechanical installation and electrical wiring and reducing potential points of failure. Improved performance and reliability: High rigidity: Direct connection between the motor and reducer eliminates errors and inconsistencies introduced by couplings. High precision: The encoder directly detects the position of the motor shaft or output shaft, ensuring high closed-loop control accuracy. The reducer's low backlash further guarantees positioning accuracy. High responsiveness: Fast internal communication speed, shorter control cycle, and faster dynamic response. Intelligent and easy-to-use: Built-in rich motion control functions, such as point-to-point, electronic cam, and synchronous tracking. Supports software parameterization settings and debugging, eliminating the need for complex external controllers. Features online status monitoring, fault diagnosis, and early warning functions. Reduced costs: Although the unit cost may be higher, it saves on installation time, wiring costs, cabinet space, and subsequent maintenance costs, resulting in a more advantageous overall cost of ownership.

[0030] In one specific embodiment of this application, the first motion component 21 further includes a coupling 4, one end of which is connected to the servo motor 22, and the other end is connected to the ball screw. A servo motor is an engine that controls the operation of mechanical components in a servo system; it is a type of auxiliary motor with indirect speed change. Servo motors can control speed, have very accurate position, and can convert voltage signals into torque and speed to drive the controlled object. The rotor speed of a servo motor is controlled by the input signal and can respond quickly. In automatic control systems, it is used as an actuator and has characteristics such as a small electromechanical time constant and high linearity. It can convert received electrical signals into angular displacement or angular velocity output on the motor shaft. Servo motors are divided into two main categories: DC and AC servo motors. Their main characteristic is that there is no self-rotation when the signal voltage is zero, and the speed decreases uniformly as the torque increases.

[0031] In one specific embodiment of this application, a bearing fixing seat 5 is further provided at the lower end of the coupling 4, and the distance between the bearing fixing seat 5 and the coupling 4 is no greater than a first predetermined distance. The first predetermined distance allows the first moving component 21 to be arranged more compactly, reducing the space occupied.

[0032] In one specific embodiment of this application, a ball screw nut 6 is provided below the bearing mounting seat 5. A high-precision ball screw is used instead of a traditional through screw. Through its line contact rolling friction design with the ball screw nut, the ball screw has higher load-bearing capacity, rigidity, and impact resistance, effectively dispersing load stress and reducing deformation and vibration caused by load changes.

[0033] In one specific embodiment of this application, the first motion component further includes a heat sink 8, which is disposed on the outside of the coupling 4, with one end connected to the servo motor 22 mounting base and the other end connected to the bearing mounting base 5. This effectively absorbs and transfers the heat dissipated by the servo motor and bearing.

[0034] In this embodiment, the heat sink 8 is attached to the bottom plate of the housing 1. An optimized reducer and electromagnetic design, along with a self-developed heat dissipation system, improves heat dissipation speed, achieving a peak torque density of 37.85 Nm / kg for the motor. The assembly process is simple, and the coupling 4 ensures a good fit with the lead screw. The heat sink effectively transfers heat to the housing, improving heat dissipation efficiency.

[0035] In semiconductor manufacturing, wafer transport is crucial for IC production. To ensure wafer quality during transport between different processes and to prevent dust or other contamination, increasingly more transport operations utilize standard transport containers, employing Standard Mechanical Interface (SMIF) technology. This system reduces wafer contamination by significantly minimizing the amount of dust flowing over the wafer. This effect is achieved mechanically by ensuring that the gas surrounding the wafer remains relatively still relative to the wafer during transport, storage, and most processes, and preventing dust particles from the external environment from entering the wafer environment. SMIF technology centers on the concept of "isolation technology." Isolation technology aims to prevent product contamination by enclosing the wafer in an ultra-clean environment while relaxing cleanliness requirements outside this enclosed environment.

[0036] The present invention also provides a novel SMIF ball screw drive method, applicable to any of the novel SMIF ball screw drive systems described herein, the method comprising: driving a ball screw via a servo motor to transport a wafer along the SMIF ball screw to achieve high-precision linear motion.

[0037] The typical operation of SMIF is as follows: Operators or automated material handling systems deliver SMIF wafer cassettes to the SMIF loading port; when the automatic batch tracking system identifies the correct product batch being loaded into the correct equipment, the SMIF loading port automatically opens the SMIF wafer cassette, removes the wafer, and places it in the equipment within the cleanroom for the appropriate processing step; once this process step is complete, the wafer is returned to the SMIF wafer cassette and subsequently carried by operators or transported by the AMHS system to the next process step. Specifically: Connect the teach pendant cable to the SMIF debug interface; The teach pendant powers on and starts normally; proceed to the next step. Select the operation controls on the teach pendant page; After the pop-up window appears, select the leftmost item in the bottom column of the page, "Arm Controls," and then click the up and down arrows on the page to move your arm.

[0038] The present invention also provides a computer-readable storage medium storing computer instructions that, when executed, cause a computer to perform a new SMIF lead screw drive method.

[0039] In one exemplary embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the steps in the above-described method embodiments.

[0040] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0041] The above are merely embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural transformations made based on the content of the present invention specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A novel SMIF lead screw drive system, characterized in that, include: The housing has a groove structure; The motion part includes a first motion component and a second motion component. The first motion component is disposed on the upper part of the housing and fixed on the bottom plate of the housing. The second motion component is disposed on the lower part of the first motion component. The second motion component moves vertically up and down along the inner wall of the housing under the drive of the first motion component. The first motion component is driven by a servo motor. The SMIF lead screw, which is a ball screw, is disposed between the first motion component and the second motion component. The first motion component drives the second motion component to transport the wafer through the ball screw.

2. The new SMIF lead screw drive system according to claim 1, characterized in that, The first motion component adopts an integrated design that combines a reducer, motor, and driver into one unit.

3. The new SMIF screw drive system according to claim 1, characterized in that, The first motion component also includes a coupling, one end of which is connected to the servo motor and the other end of which is connected to the ball screw.

4. The new SMIF lead screw drive system according to claim 3, characterized in that, The lower end of the coupling is also provided with a bearing fixing seat, and the distance between the bearing fixing seat and the coupling is not greater than a first predetermined distance.

5. The new SMIF lead screw drive system according to claim 4, characterized in that, A ball screw nut is provided below the bearing mounting base.

6. The new SMIF screw drive system according to claim 3, characterized in that, The first motion component further includes a heat sink, which is disposed on the outside of the coupling and connected at one end to a servo motor mounting base and at the other end to a bearing mounting base.

7. The new SMIF screw drive system according to claim 6, characterized in that, The heat sink is attached to the bottom plate of the housing.

8. A novel SMIF screw drive method, applied to the novel SMIF screw drive system according to any one of claims 1 to 6, characterized in that, The method includes: The servo motor drives the ball screw to transport the wafer along the SMIF screw, achieving high-precision linear motion.

9. A computer-readable storage medium storing computer instructions, characterized in that, When the computer instructions are executed, the computer performs the new SMIF screw drive method of claim 8.

10. This application provides a computer device comprising a processor and a memory, characterized in that, The memory stores computer instructions that are operated by a processor to execute the new SMIF screw drive method of claim 8.

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